Re: It's at the Machine Shop
 

Man that sucks to hear. If you can find a replacement 305A, possibly from one of the forum members here, that'd be the way to go.

Re: It's at the Machine Shop
 

It makes no sense to rebuild a GMC 305 V6. Fixing semi small issues is OK. These motors have virtually no parts left, no one knows anything about them and they are, for the present, available for a low price from non believers. Find a donor, hear it run and/or do a compression test. Check the oil. Keep your old one for the bolt on parts.

An easier option
If you like the truck and not worried about if it has a GMC 305A V6, Drop in a SBC. A SBC is a GM product. Lighter, faster, HEI, parts galore. That wouldn't hurt anything. Gives you the chance for any trans, manual or automatic with OD. Everything fits everything. Don't obsess over a GMC 305 V6. The truck itself is very nice to own.
Change course, be happy.

P.S. I didn't search your posts, so I don't know why you are rebuilding it?????????????

Re: It's at the Machine Shop
 

'

:ahhhh::machinegun::machinegun:

Re: It's at the Machine Shop
 

It's the second option man :tiphat: Trying to help the gentleman. Ease his mind and his wallet. A brainstorming session. Inflexibility killed the cat. I didn't say throw out the truck with the motor. :getrdone2:
Waly mentioned it first.

Re: It's at the Machine Shop
 

If you end up replacing your 305, keep your eyes and ears open for a truck engine too (351 v6), it could be easier to find.
It’s a direct fit, although you’ll have to swap your light truck parts (front of engine and bell housing). Then you have a running and larger engine. I’m currently running a 5000 series 351 in my half ton and have another 4000 spare.

Re: It's at the Machine Shop
 

Bet the 351 has some added 'git up and go' compared to the 305?

Re: It's at the Machine Shop
 

Hang in there, it seems we are all having some issues. My block stock bore block cannot be used, found a crack, so my replacement block has already gone .030 over and it had a broken piston in it. I have some really nice .040 pistons/triple rings, waiting to hear if I can make it work, might need a sleeve myself. If it needs more than one sleeve, I might punt the football and sell all my bearings/pistons rings and gaskets. Sleeving the cylinder is pretty expensive these days.
Steve

Re: It's at the Machine Shop
 

I rest my case.....................Fetch. :egyptian:

Re: It's at the Machine Shop
 

Okay, so back to looking at the engine again.

My brother is the engine guy, of the two of us, and he thinks we'd be better off just putting it back together. Having the heads done at the machine shop, get new sleeves/bearing etc. and maybe have the crank turned...but then just put it back together. Which means I would still need to find rings.

The only problem it ever had was the oil pump started squealing right before I tore it down, it was seeping at various gaskets/seals, and there had always been a valve issue with it if the timing wasn't set out of specs (don't ask, I have no idea but clearly something in the heads). It never smoked at all, really it ran great. Kinda back to ticked that I got talked into tearing it apart in the first place now.

Anyway, that's what I think we're going to do. I talked to the machine shop and they're going to do the heads for $150 and would polish the crank for $20, but I was just looking at it and I think it's going to need turned, as it is a bit scored in places.

Re: It's at the Machine Shop
 

Great to here, I just finished my 305 and have somethings left from my rebuild.
Machined crank and set of .020/.020 main and rod bearings. Found out my engine was a 1974 305 and took a different main bearing (bigger), so the main bearings are for 60-73 motors.

Good luck with the rebuild. Dont forget to replace the oil pump, I found out there are two different ones to based on the size of the oil mounting bolt. They are NOT interchangeable.